Telephone systems, such as the public switched telephone network (PSTN), often intercept calls attempted by a customer that cannot be completed as dialed for any of a variety of reasons, such as a disconnected subscriber, the dialed number being out of service, or the dialed number being reserved for other uses. The telephone system typically directs the caller to an intercept system and the intercept system may then communicate the unavailable status of the dialed number to the caller, via a recorded voice message or sequence of tones transmitted back to the caller. For example, the intercept system may playback recording informing a caller that the number cannot be completed as dialed, the number is not serviceable from the caller's area code, the number is not in service, the number is disconnected, that a zero, one, and/or area code should be dialed when calling the number, and the like. Such intercept systems are disclosed, for example, in U.S. Pat. No. 4,446,337 to Cofer and U.S. Pat. No. 4,791,666 to Cobb, et al.
While useful in indicating to the caller that the attempted call cannot be completed as dialed, a limitation common to conventional intercept systems is that they typically provide minimal, if any, additional information regarding the status of the dialed number other than it has been disconnected, out-of-order, or otherwise unavailable. For example, when a caller dials a disconnected number, the recorded message transmitted to the caller over the telephone network generally includes a variation of the phrase: The number you have dialed has been disconnected or is no longer in service. Please check the number and try again. This is followed by a disconnection of the call. Accordingly, the resulting message provides the caller little insight as to why the dialed number is unavailable.
To remedy the situation, the caller typically must disconnect, or hang up, from the call and place a second call to a directory assistance service (DAS) to obtain additional information regarding the unavailable number or to obtain an alternate telephone number, thereby causing considerable inconvenience to the caller. Examples of directory assistance services are disclosed, for example, in U.S. Pat. No. 3,928,724 issued to Byram, et al., U.S. Pat. No. 4,979,206 issued to Padden, et al., U.S. Pat. No. 4,959,855 and U.S. Pat. No. 4,918,719, both issued to Daudelin.
When a call is placed to a directory assistance service, the caller usually provides one or more descriptors, such as a name, telephone number, or address to the service via either an operator or through voice recognition software. The directory assistance service then searches one or more databases for information associated with the descriptors and provides the information, if any, to the caller either via an operator or by an automated voice synthesis system. However, to take advantage of the benefits of directory assistance, the caller generally must have prior knowledge of the specific telephone number used to reach the directory assistance (e.g., 865-555-1212 or 411). To further complicate matters, there are a number of local, regional, and nationwide directory assistance services. Accordingly, a caller unfamiliar with a certain locality or region may not have offhand knowledge of the number used to contact the local or regional directory assistance associated with the area. As a result, the caller typically must spend considerable time and effort in locating the directory assistance number before the caller can obtain information regarding the caller's previously unsuccessful telephone call to the unavailable number.
In view of the limitations of known intercept systems and directory assistance services, a system and method for providing directory assistance to customers attempting to place calls to unavailable numbers would be advantageous.